Indicator for radio devices



Sept. 24, 1929. D. R. LOVEJOY INDICATOR FOR RADIO DEVICES Filed Nov. 28, 1925 @o A t P/ WITNESS Patented Sept. 24, 1929 l UNITED STATES PATENT ori-ICEA DIMIVIITT ROSS LOVEJOY, OF NEW YORK, N. Y., ASSIGNOR TO LOVEJOY 'DEVELOPMENT' CORPORATION, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK Application filed November My invention relates in general to means for actuating the rotary elements of radio control devices, such as condensers, inductances, rheostats, and the like which are ordinarily mounted on the panelof the set.

The so-called tuning dial in the radio art has, under modern development, come to be a recognized article of manufacture which can be purchasedv on the market and applied to the projectingshaft of the control device it is intended to actuate. At the present time, such dials are mostly employed on the condenser shafts andare provided with a scale or pointer to indicate the extent of the rotary movement of the condenser vrotor by which the tuning of a circuit is adjusted. In the present condition of radio transmitting stations having Wave length assignments bordering closely on each other, the necessity for accurate tuning has become acute and many of the actuating dials areprovided with socalled Vernier actuation in order to obtain closer adjustment of the condenser rotor. In most of these an exact and definite proportion of the movement of the main dial With relation to the Vernier actuation is not ab# solutely insured, on account of the use of uncertain frictional drive, and even Where the drive ma y be more or less constant and fixed, such as by gearing, back-lash may still occur to render the problem .of repeating a very exact setting of the condenser over and over again, a very diiiicult one. Whether due to this mechanical difficulty or not, the fact remains that in.A none of the forms heretofore produced hasfthere been any possibility of, or provision for, observing with micrometri'c sharpness`theexact -position of the condenser setting and recording the sameso that the saine position vor, setting may be repeated Iwithout difficulty. K y

Anv objectof the lpresent invention is prima rily to provide ay construction for actuating and indicating with great accuracy the adjustment of the condenser or other radio con- .trol device, so that the precise setting maybe rccordedand repeated Without difficulty.

An example of the principle of construction and operation in which I attain the advan tages of the present invention Will be de- 28, 1925. Serial No. 71,973.

scribed, in connection with its use upon arotary condenser, as illustrated in the accompanying drawing. l V v In said drawing, Figure 1 is a vertical sec,-

Ation, in an axial direction, showing acondenser mounted upon a panel and having on its shaft an embodiment of the indicating and actuating mechanism vforming the subject matter of the invention.

FigureQ is a face view of the indicating and actuating mechanism shown in Figure 1, with a part of the housing broken away.

Figure 3 is a detail face view of the proportionate drive-connection inthe form of gear and pinion, as seen from the rear on the line 3 3 of Figure 1.

Figure 4 is a detail view, as seen from the rear on line 4 4 of Figure 1, illustrating the construction by which the torque reaction on the-pinion is taken up.

Referring now more specifically to said drawing, 1 `indicates the condenser shaft having 'fixed thereon,`by soldering or otherwise, the set of movable plates 2, which are rotatable between the fixed plates 3 of the condenser. The construction of the condenser is vnot in itself a featureofthe present invention and I have .illust-rated only enough to make clear the application of the invent-ion. The condenser is mounted in any, approved or ordinary manner upon the 4back of the panel 4, with the rotor shaft l projecting forwardly thru a perforation in the panel. i

The invention contemplates in a general way, a plurality of rotary members or elements Which are interconnected for proportionate movement and have'related to them scale or indicating devices by which the proportionate movement ofthe respective rotary elements may be graduated to extreme fineness. Forallordinary purposes two of such rotary elements will be sufficient and the scale applied to lone may be `marked 0H in units of complete turns of the ot-her,-whereas the scale applied tothe othei-may be marked off in degrees or 'any suitable number of subdivisions one complete revolution.

The example illustrated embodies two of suchI rotary members, one of which may preferably bc mounted upon the rotary shaft l of y the condenser or other analogous device and observed that the rotary element 5 is inthe y8,1m clearly form' of a disk which is thus effectively clamped in fixed position between the gear 7 and the shoulder of the hub 6 so that these three parts move in unison with the condenser shaft 1 and the rotary plates 2. A scale may be conveniently a plied to `the face of disk 5 near its outer-e ge, tovbe rea-d thru asight opening9 rin thehousing 8 in conjunction with'av stationary reference pointer 10, as clearly shown in Figures 1 and 2. The housin 8 is fitted over the hub 6, and .may be -he d in place thereon by a cap 6', vagainst the frontface of the shoulder of the hub. The hub however, is free toturn in the perforaf vtion thru which it passes in the front wall of the housing 8. f

The second rotary element, in the formof a disk 11, is fixed on the rear face of a turning knob 12 which is journaled on 'a tubular post 13 inserted'in a perforation in the lowerportion ofthe housing 8 and secured'to the hous` wall by means of the nut 14 which-is threaded Jon to the inner end of the post. A floating shaft 15 has its forward end firmly i. fitted into a socket or recess axially disposed withinA ther knobv 12 and is held therein by means of set screws'16, or in any other suitable manner. This floating shaft 15 passes rearwardl thru the tubular post 13 and terminates )ust short of the panel 4 where it carries a s urpinion 17 which is fixed on the floating end, of the shaft and held firmly in mesh with the teeth of the gear 7 above described by suitable nieans such as a resilient wire-18 having its bent ends 19 fitted into radial perforations or recesses formed in the rim flange of housing shown in Figure 3.' This spring presses reslliently against the projecting rear end oflloating shaft 15 and thusurges-the pinion 17 toward the gear-7. With this construct tion, I- prefer to employ a special provision for taking upthe torque reaction of the spur-gear 17, such as illustrated for example in Figures 1and4. This feature comprises the slotted end wall or disk 20 at the rear of tubular post 13`thru which the shaft 15 passes. The slot in this wall or disk 20 is disposed radially of the gear 7 so that the re'silientwire 18 is not opposed in its vfunction 'of urging the spur gear toward the gear 7 but any .non-radial movement qr swinging of the inner end of floating shaft 15 `is effectively prevented. Shaft 15 is of such a character and of hysical dimensions as toyield under the in uence of the resilient wire 18fand hence thel necessity of resisting the torque reaction by some spe.

cial construction other than the stiffness or the rigidity of the sha-ft itself vThe mounting of the dials and housing upon the condenser shaft '1 in the manner described requires no particular provision yfor further su porting the/*parts in osition on the fronte the anel, but it is o course, necessary to preven lthe housing from'turning or swingi 0. This action may conveniently be prevented by passing a screw or bolt 22 thru the housing 8 and into ya perforation or recess in` the panel/1. In

" rovides a very accurateproportionate moveent of the two rotary members so that a` .micrometric scale may be applied to the respective parts and relied upon to enable the operator to record and reproduce a` critically exact setting vof'the control device.

The disk 5 is here shown by way of example circumference of disk 5 into ten ual ear 7 it is,'.of-course, neceary as being 'calibrated in units, each of which divisions each representing one comp ete turn ofthe disk/11, the exact lsetting can always be read in three figures.` For example, if the dial of disk 5 indicates between the division point 3 and division point 1 1 with reference to the -pointer 10, and the scale of disk -11 reads 7 divisions 'from a fixed reference line on the face of 'the housing, the condenser settin 307 will be very easily read. and recorde and f may be reliably reproducedsat any]7 time. Without the proportionate relations ip between the motion of disk andthe motion of disk 1 1 being accurately maintained, or even with a reliable proportionate movement but with no way of reading accuratel the position v of disk 11, the recording of t e control setting and its subsequent: re-setting to the precise position with a nice degree of accuracy would be unattainable.`

I claim:

1. A micrometric indicator for rotary radio control devices, comprising in combination a pair of rotary elements, one of which has means -for operatively connecting it with the rotor olf the radio control device, to be actuated, a gear and a pinion mounted on the respective rotary elements, means for resiliently urging saidpinion radially toward said gear, and a guide Way for preventing the devia-tion of said pinion from such radial path.

2. Apparatus of the character described comprising in combination a gear, a tubular post having a guide slot at its inner end, directed toward said gear, a qturning knob journaled on said tubular post, a shaft fixedly secured at its forward end in said turning knob and extending rearwardly thru said tubular post and the slotted rear end thereof,

a pinion fixed on the free inner end of said 1 shaft beyond said tubular post, and ineshing with said gear and means for resiliently urging the free end of said shaft toward said gear in the direction of said guide slot.

DIMMITT ROSS LOVEJ OY. 

